Message to teams playing 49ers after loss: Look out

Call it an oddity, a sign the 49ers are foaming-at-the-mouth angry after a setback, or evidence that Jim Harbaugh is a motivational maestro.

Whatever the case, San Francisco’s remarkable streak continued in Thursday night’s 13-6 win over Seattle: It still hasn’t allowed a touchdown in games after a loss in the Harbaugh era.

For the fifth time in as many chances since 2011, a bounce-back win was headlined by a suffocating defensive performance. San Francisco has won its post-loss games by a combined score of 106-17, with two of those 17 points coming as a result of a safety punter Andy Lee took by stepping out of the end zone near the end of last year’s 13-8 win at Cincinnati.

In the latest edition of We Refuse to Lose Two Straight, the 49ers limited Seattle to four first downs and 74 yards in the second half. Were they ultra-motivated after they were pushed around in the fourth quarter of last week’s 26-3 loss to the Giants?

Linebacker Patrick Willis, whose performance against New York was criticized by NFL Network analyst Matt Millen, said the 23-point defeat provided an extra impetus.

“Coming off a loss, we wanted to go out there and get that mojo back,” said Willis, who had eight tackles and defended two passes.

“I mean, the main thing is winning and losing,” he said. “Reasserting yourself? I don’t really care one way or the other. Just do what you’ve got to do defensively and offensively to win the game. We were able to do that.”

** Jim Harbaugh hasn’t lost back-to-back games since 2009 when he was at Stanford. The Cardinal lost 38-28 at Oregon State on Oct. 10, and followed with a 43-38 loss at Arizona on Oct. 17.